Comparison of Plasma Osteopontin Levels between Patients with Borderline Ovarian Tumours and Serous Ovarian Carcinoma.

Osteopontin (OPN) is a novel biomarker of various cancers including ovarian carcinoma. OPN is a promising adjunct to a major biomarker of ovarian cancer, CA125, in diagnosis, differential diagnosis and prognosis. The aim of our study was to measure the plasma level of OPN and CA125 in patients with borderline ovarian tumours (BOTs), serous ovarian carcinoma, and controls to determine its potential role in the differential diagnosis between serous ovarian carcinoma and BOT. The plasma samples of 66 women were analysed using Luminex technology, designed to simultaneously measure multiple specific protein targets. The mean OPN plasma level for the control group was 23.3 ng/ml; for BOT 26.3 ng/ml; and for patients with serous ovarian carcinoma 59.5 ng/ml. Specifically, there was a significant difference between the OPN levels in patients with ovarian carcinoma and BOT (P < 0.001) as well as controls (P < 0.001). There was no difference between the mean levels of OPN in patients with BOT and the control group (P = 0.286). Using the receiver operating characteristic (ROC), we determined the utility of OPN and CA125 to differentiate between BOT and serous ovarian carcinoma. The area under the ROC curve (AUC) for OPN was 0.793 (95% confidence interval (CI) 0.669-0.917, P < 0.001) and for CA125 0.766 (95% CI 0.626-0.907, P = 0.002). Based on our data, we suggest that OPN can be used as a possible differential diagnostic biomarker to distinguish between malignant serous ovarian carcinoma and BOT.